1. Field of the Invention
The invention relates to a scroll type compressor, and more particularly to a scroll type compressor having a pressure adjusting valve.
2. Description of the Related Art
A conventional scroll type compressor is a positive displacement and constant speed compressor. The volumetric ratio and the compression ratio are constant. When the variation of load causes the inlet and outlet pressure to change, the volumetric ratio and the compression ratio must also change. The conventional scroll type compressor, however, has a constant volumetric ratio and compression ratio, thus, over-compression or under compression results in degrading efficiency of the conventional scroll type compressor.
U.S. Pat. No. 6,913,488 discloses a compressor with a device load adjustor. The compressor includes a slider and a scroll for adjusting load variation to maintain a constant compression ratio. The inlet pressure is compressed and then discharged by the outlet. The variation of load does not affect the compression ratio, thus, the inlet and outlet pressure are not controlled.